Eleven macaques (4 rhesus, 1 pig-tail, and 6 long-tail) found to be naturally infected with various serotypes of Simian type D retrovirus (SRV/D) during routine colony and quarantine screening, will be maintained in BSL-2 housing to provide blood and other biological samples for use in the development of enhanced diagnostic techniques, including polymerase chain reaction (PCR) for the detection of integrated proviral DNA; reverse transcriptase (RT)- PCR for the detection of viral RNA in plasma and other body fluids; and synthetic peptide based enzyme immunoassays for detection of SRV/D-specific antibodies. To date, gag and env PCR primer pairs have been developed that are capable of recognizing SRV serotypes 1,2,3 in infected cell cultures, peripheral blood and lymphoid tissues. Development of pol gene primers able to recognize all 5 known SRV serotypes is currently in progress.